Precise hardening with high-power diode lasers using beam-shaping mirror optics

Abstract

Heat Treatment is one of the most promising application of multi kilowatt high power diode lasers. Providing a sufficient beam quality HPDL's have the advantage of their high efficiency comparing to Nd:YAG-lasers. Application of scanning mirror optics for multi kilowatt lasers is well known at CO₂- or Nd:YAG-lasers. Fraunhofer IWS has developed a special driver unit, which generates automatically an optimized scanning function to provide a stress adapted intensity profile. Know the application of this technology at multi kilowatt high power diode lasers has been implemented successfully. Using 2.5 kW diode laser power hardening tracks of 30 mm in width and a penetration of about 1 mm are possible. Applying the temperature guide laser power controller LompocPro additionally, stress adapted hardening of edges with varying cross sections became possible. Besides hardening this system allows heat treatment with a rectangular beam of 5 x 85 mm². Some applications show the performance of this technology.